from selenium import webdriver
from selenium.webdriver.common.by import By

driver = webdriver.Chrome()
driver.get('http://192.168.20.244/ecshop/admin')
driver.maximize_window()

driver.find_element(By.NAME, 'username').send_keys('caichang')
driver.find_element(By.NAME, 'password').send_keys('caichang1')
driver.find_element(By.ID, 'tijiao').click()

driver.switch_to.frame("menu-frame")
driver.find_element(By.XPATH, '//*[@id="menu-ul"]/li[2]/ul/li[1]/a').click()

driver.switch_to.default_content()

driver.switch_to.frame("main-frame")
driver.find_element(By.XPATH, '//*[@id="listDiv"]/table[1]/tbody/tr[3]/td[5]/img').click()